30 patients American society of anesthesiology (ASA) physical status I,II and III undergoing general anesthesia for elective transurethral resection of the prostate (TUR-P) surgery will be included in the study. Patients will be randomized into two groups; first group(control group) and second group (forced-air warming). Resistive heating will start when patients are transferred to the operating room table; forced-air warming will start before preoperative 30 minute.